1. Field of the Invention
The present invention relates to a motor mechanism which can be generally utilized as a motor for all kinds of industries, particularly, for a vehicle. Further, it can be used a speed changer.
2. Description of the Prior Art
A power motor having a wide range of power revolution (rotation) number and power torque, especially an electric motor means used as a driving means for a vehicle can be used without any speed change gear, directly driving, or used through a speed change gear. In the prior art motor, when no speed change gear is used for directly driving, it is difficult to control in the range of low speed because the internal resistance is lower of the high performance motor.
A power of a motor can be controlled or adjusted by raising or lowering a voltage being applied or by switching on-off. Higher the voltage being applied is, higher the power of a motor is. The power of the motor can be lowered by reducing the voltage applied. The current flowing in the circuit will change in proportion to the voltage. Therefore, the increase of the voltage will increase the current amount. Where the voltage is the same, lower the resistance is, higher the current flows so that the power of the motor will increase.
The torque generated by a motor will increase proportionally to the current. Further, When the velocity of a vehicle should be raised in driving on a flat road, the voltage should be increased to raise the revolution number. When the the velocity should be constant even in climbing up a slope road, the voltage should be increased so as to raise the torque with maintaining the speed of the vehicle. Then, the velocity and the torque can be changed in combination by adjusting the voltage applied to the motor. This is corresponding to that the revolution (rotation) number and the torque of the motor can be changed by pressing an accelerating plate.
A motor gives maximum torque at the time when the revolution number is 0. The higher the revolution number is, the lower the torque becomes. When the high speed rotation is without any load, the torque will be less and approach to 0. Such relationship of T-N can be indicated in a graph of FIG. 1 showing that the revolution number will decrease when the torque increases. Another feature of the motor is a T-I curve as shown in FIG. 2, indicating that the increase of T will increase in proportion with I. That is, the higher the torque is, the higher the consumption of the current will be, so as to raise the current, thereby increasing the torque. Then, a high performance motor will have sharper slope of the curve T-N. The maximum torque of high performance motor will be 4.5 times of that of a regular motor, and therefore, higher current will flow in such high performance motor. The torque T is T=KI, where K is torque constant, I is current, E is voltage, and the resistance of the motor is R. Then, I=E/R, and the energy loss generated by flowing an electric current through a motor is W=R.times.I.sup.2, generating a heat within coils in the motor. Especially, in a high performance motor, a maximum torque (traction) can be maintained for long period of time at the revolution number of 0, but a very large current will flow in the motor, resulting in excessive heating to be short-circuited possibly into firing. A high performance motor has relatively low resistance so that electric current flows easily, and then, it is very difficult to operate at the lower rotation number. Further, a high performance motor in which eddy currents and copper loss and excessive heat will occur in the range of the revolution number to be cut is difficult to be operated. When the revolution is reduced, higher current flows in the motor. Therefore, a high performance motor requires a current control circuit. It is possible to fail controlling an excessive current by noise or some circuit fail, and then the motor can be broken by the excessive current, and it is difficult to operate smoothly a high performance motor.
Generally speaking, there is a drastic change of load when a power motor is used under high loading condition in a wide rotation range. For example, when reverse rotation force is loaded on the final driving shaft, an excessive current is applied on the motor to be broken or a overloading is applied on a source controlling system. A voltage control will enable to adjust the rotation speed and the torque as applied on the final driving shaft, but it needs detecting the rotation and the torque as applied. When some heating will loose controlling of the motor, the motor will be broken or a source circuit will be overloaded. Further, when responsibility is not good, an excessive power consumption will be higher.
A high power motor is difficult to operate at the time of zero revolution number and high torque loaded, and further, it needs high power, and then, a heat-proof or heat-prevention means will be complicated, and costly, and further it will raise a possibility of errors.
There is disclosed in Japanese Patent Application Laid-open gazette No. 4-185,205/1994 a motor means in which one motor can be used as a generator to regenerate. This motor means has a motor, a driving circuit, a driving battery, a helping battery, a regenerative adjusting means including a control circuit; and further a regenerative alternating means, a regenerating means of regenerating a power generated by a motor into a driving battery and a regenerating means of regenerating a power generated by a motor into a helping battery.